Index: docs/pdds/draft/pdd16_native_call.pod
===================================================================
--- docs/pdds/draft/pdd16_native_call.pod	(revision 42386)
+++ docs/pdds/draft/pdd16_native_call.pod	(working copy)
@@ -92,10 +92,12 @@
 
 =item p
 
-PMC thingie. A generic pointer, taken from or stuck into a PMC's data
-pointer.  If this is a return type, parrot will create a new UnManagedStruct
-PMC type, which is just a generic "pointer to some damn thing or other" PMC
-type which Parrot does I<no> management of.
+PMC thingie. A generic pointer, taken from a PMC by using his
+get_pointer vtable function, or NULL for a PMCNULL.
+If this is a return type, if the value is NULL PMCNULL is returned,
+otherwise parrot will create a new UnManagedStruct PMC type, which
+is just a generic "pointer to some damn thing or other" PMC type
+which Parrot does I<no> management of.
 
 =item 2